(Reuters) – European Union leaders on Saturday chose Poland Prime Minister Donald Tusk to chair their Council and named Italian Federica Mogherini to run the bloc’s foreign relations, as the EU prepared to threaten Russia with new sanctions overUkraine. A summit in Brussels shared the two coveted EU posts between a Kremlin critic from ex-communist Eastern Europe and the foreign minister of one of Moscow’s biggest customers for gas. EU officials gave Ukraine’s embattled President Petro Poroshenko […]